Medium-high voltage power supply quality unified regulator containing distributed energy storage unit

Abstract

The invention discloses a middle-high voltage power supply quality unified regulator containing a distributed energy storage unit. The regulator comprises an alternating current power grid access end, an input switch, a phase-shifting transformer, n three-phase rectifiers, an MMC (modular multilevel converter), an output switch, a load access end and a bypass switch, wherein six bridge arms of the MMC consist of cascaded composite submodules SM; the composite sub-module SM is composed of an MMC sub-module and an energy storage module. The n secondary three-phase windings of the phase-shifting transformer are connected to the alternating-current input ends of the n three-phase rectifiers in a one-to-one correspondence mode, direct-current output ends of the n three-phase rectifiers are connected to the direct-current end of the MMC converter in a cascaded mode, and a load voltage is output through the MMC converter, so the number of the phase-shifting transformer windings and the number of the three-phase rectifiers are greatly reduced; and the energy storage module can independently supply power to the load through a cascade bridge formed by three upper bridge arms and three lower bridge arms of the MMC converter, so transmission efficiency of the system is improved.

Description

technical field [0001] The invention belongs to the technical field of electric power transmission and distribution, and more specifically refers to a medium-high voltage power supply quality unified regulator including a distributed energy storage unit, which is used to ensure safe and reliable power supply for users. Background technique [0002] With the rapid development of global industrialization and informatization, the comprehensive improvement system of high-power power supply quality is more and more widely used in important loads with large capacity due to its superior power supply performance. In the existing high-power power supply quality comprehensive improvement system, the cascaded H-bridge type medium-voltage uninterruptible power supply (Uninterruptible Power System, UPS) with phase-shifting transformer is characterized by its small grid-side harmonics, high degree of modularization, and large system capacity. , good redundancy characteristics and other ad...

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Problems solved by technology

[0004] In order to solve the technical problems existing in the existing power supply quality comprehensive improvement system, the present invention provides a medium and high voltage power supply quality unified regulator with distributed energy storage units, which greatly reduces the secondary winding of the phase-shifting transformer and the three-phase rectifier. The number, system modularization and reliability are all effectively improved, effectively reducing the influence of the MMC converter DC current on each bridge arm, and improving the system power transmission efficiency

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